The proposed instrumentation for rapid sorting and staining of cellular samples will provide a convenient tool in a number of cellular analyses and manipulations including diagnoses (e.g., for isolation of circulating tumor cells or circulating feal cells) and therapies (e.g., hematopoietic stem cells transplantation, stem cell based regenerative medicine) based on rare cell isolation from blood or other tissues. While this proposal focuses on simple cell sorting and staining protocols and analysis of cells by multicolor flow cytometry, this versatile, modular system will allow the efficient collection and efficient preparation of cellular samples for a wide variety of clinically relevant analyses such as genotyping/phenotyping assays (e.g., tumor genotyping), drug or chemosensitivity assays, drug reactivity profiles, mutational analyses and high-throughput gene sequencing. The proposed instrumentation will thus have potential impact across a wide cross section of medical applications and general relevance to the improvement of public health.